JSON Parsing in Swift 4 - json

Question

I'm quite new to Swift and i am trying to return a string from my parsed JSON array. I'm not sure how i use the "arrayString" var in another class as i haven't "declared" it in the other class. I assume it has something to do with it being in URLSession. Any tips on what i could do?
struct Games: Decodable {
let videoLink: String
}
class BroadService: NSObject {
static let sharedInstance = BroadService()
func fetchBroadcasts(completion: #escaping ([Games]) -> ()) {
let jsonUrlString = "LINK IS HERE."
guard let url = URL(string: jsonUrlString) else { return }
URLSession.shared.dataTask(with: url) { (data, response, err) in
guard let data = data else { return }
do {
let json = try JSONDecoder().decode([Games].self, from: data)
let arrayString = (json[linkcell].videoLink)
} catch let jsonErr {
print("Error serializing json:", jsonErr)
}
}.resume()
}
This is my code at the minute, It's not the most neat thing in the world, but it gets the job done.

Answer 1

There are several issues with your code:
You needlessly extend NSObject.
You never call the completion block.
arrayString is not an array.
Your completion block should at least make the Games array optional to indicate an error.
Here's how your code should be:
struct Games: Decodable {
let videoLink: String
}
class BroadService {
static let sharedInstance = BroadService()
func fetchBroadcasts(completion: #escaping ([Games]?) -> ()) {
let jsonUrlString = "LINK IS HERE."
guard let url = URL(string: jsonUrlString) else {
completion(nil)
return
}
URLSession.shared.dataTask(with: url) { (data, response, err) in
guard let data = data else {
completion(nil)
return
}
do {
let games = try JSONDecoder().decode([Games].self, from: data)
completion(games)
} catch let jsonErr {
print("Error deserializing json:", jsonErr)
completion(nil)
}
}.resume()
}
}
Then you can call it as follows:
BroadService.sharedInstance.fetchBroadcasts { (games) in
if let games = games {
// Process all games if needed
for game in games {
let videoLink = game.videoLink
// do something
}
// Or access a specific game:
let game = games[someIndex]
let videoLink = game.videoLink
// do something
}
}